This invention relates to hand tools, and in particular to hand tools such as a hex key, screwdriver, screwdriver bits or the like for applying torque to a fastener.
A common problem in all such situations is that as the torque is applied, the tool tends to slip out of the fastener, particularly but not only when the tool does not fit the fastener precisely due to tolerance variations, wear and tear on the tool and/or fastener, or other reasons. The greater the torque applied, the greater the tendency for the tool to slip or pop out of the fastener.